bash script to run a command and take screenshot in every loop.

Couple of days back, I had posted a command to display a stop timer with bash and echo. There I had also put the following gif file:

<img class="size-medium wp-image-2555" title="bash screenshot for the script output" src="http://blog.amit-agarwal.co.in/wp-content/uploads/2010/09/temp-300x170.gif" alt="bash screenshot for the script output" width="300" height="170" />

Here the tricky part was to capture the jpg&#8217;s to create the gif file.

Preparation:

1. Rename the terminal to aka – amit-capture

2. Execute the command once with the import command and check the output and jpg&#8217;s

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bash – echo command with option to display the output on the same line.

Here is a nice little trick to display the output in the same line :

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      &nbsp;<span class="kw3">echo</span> <span class="re5">-ne</span> <span class="st0">"output\<span class="es1">\r</span>"</span>
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The trick here is simple, first we disable the <a class="zem_slink" title="Newline" rel="wikipedia" href="http://en.wikipedia.org/wiki/Newline">newline printed by <a class="zem_slink" title="Echo (command)" rel="wikipedia" href="http://en.wikipedia.org/wiki/Echo_%28command%29">echo command with the &#8221;-n&#8221; option and then we enable the interpretation of the <a class="zem_slink" title="Backslash" rel="wikipedia" href="http://en.wikipedia.org/wiki/Backslash">backslash characters with the &#8221;-e&#8221; option. As the &#8221;\r&#8221; is used as <a class="zem_slink" title="Carriage return" rel="wikipedia" href="http://en.wikipedia.org/wiki/Carriage_return">carriage return which brings you to the start of the line without the newline (like in <a class="zem_slink" title="Typewriter" rel="wikipedia" href="http://en.wikipedia.org/wiki/Typewriter">typewriter), we will use the same to get the desired effect. So, if you wanted a stopwatch for a 100 seconds on the console then this simple bash <a class="zem_slink" title="For loop" rel="wikipedia" href="http://en.wikipedia.org/wiki/For_loop">for loop would do the same:

Remove some path from the PATH variable temporarily.

How many times has it happened to you that you are working on some linux platform (like Fedora/Ubuntu/CentOS etc) and suddenly you see that you need to remove some path from the PATH variable so that a script is executed from some other path. It really difficult to do this if the path is too long and if you end up doing this couple of times. If that is the case, then the below script is for you 🙂

Use the last command\’s output as input to a command without piping and bind to it to a key sequence in bash.

Use the last command&#8217;s output as input to a command without piping and
bind to it to a key sequence in <a class="zem_slink" title="Bash (Unix shell)" rel="homepage" href="http://tiswww.case.edu/php/chet/bash/bashtop.html">bash.

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      &nbsp;<span class="kw3">bind</span> <span class="co3">\'</span><span class="st0">"\\C-h"</span>: <span class="st0">"\\<span class="es5">`fc\\ \\-s\\`</span>"</span><span class="co3">\'</span>
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My comment : fc is the fix command of the bash builtin.
This is similar to using `!!` or

tee to a file descriptor

tee to a file descriptor

1

$ tee >(cat – >&2)

the tee command does fine with file names, but not so much with file descriptors, such as &2. This uses process redirection to tee to the specified descriptor.

In the sample output, it’s being used to tee to stderr, which is connected with the terminal, and to wc -l, which is also outputting to the terminal. The result is the output of bash –version followed by the linecount

Paste clipboard is bash or shell scripts with modification.

Today I had a issue where I wanted to paste the clipboard to a shell script after removing the spaces. So, I went hunting for a way to do this. Finally I came up with this:

sudo yum install xclip

Then you can paste the clipboard content using &#8221;xclip -o&#8221;. So now the problem is reduced to selecting the required info and doing :

xclip -o |sed &#8217;s/ //g&#8217;

or

CLI Color and bash prompt.. some colored fun with prompts in bash

There are two ways to do it, one is with tput command. We will see that some other time, today we will consider the escape sequence way.

First we need to understand the colors as understood by bash. Some time back a fried of mine gave me this little script to find the colors. You can download it <a href="http://blog.amit-agarwal.co.in/2009/03/bash_colors" target="_blank">Script bash colors. Here is the script

#!/bin/bash

T=&#8217;amit agarwal&#8217;   # The test text

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